A college student who claims he had same-sex attractions but was ‘cured’ after conversion therapy has filed a lawsuit against California, which has enacted a law that bans the so-called ‘treatments’ for under 18s.

Aaron Blitzer, who is studying to be a therapist in that field, believes the banning of the therapy intrudes on First Amendment protections of free speech, privacy and freedom of religion.

According to court papers filed Monday in the US District Court for the Eastern District of California, Blitzer said the law would prevent him from pursuing his career.

Two therapists who have used the treatments with their patients are in also said to be in agreement with the student.

The lawsuit names as defendants California Governor Jerry Brown, as well as 21 other state officials, including members of the California Board of Behavioral Sciences and the California Medical Board.

The other plaintiffs are Donald Welsch, a licensed family therapist and ordained minister who operates a Christian counselling centre in San Diego and Dr. Anthony Duk, a psychiatrist and practicing Roman Catholic.

Both say the law would restrict their counselling practices, according to the lawsuit.

President and attorney for the conservative Pacific Justice Institute, which asked a federal judge to prevent the law from taking effect, Brad Dacus said: ‘It’s it’s an egregious violation of the rights of young people feeling same-sex attraction, and of parents and counsellors who feel it would be beneficial for the individual needs of a young person.’

‘The legislature had an errant assumption that every individual struggling with same-sex attraction is caused by their DNA,’ he said.

"It ignores thousands, including the plaintiff, who have gone through therapy and are now in a happy and healthy heterosexual relationship.’

Just this week, California lawmakers voted to outlaw therapy aimed at changing the sexual orientation of minors who say they are gay, which will go into effect on 1 January 2013, making California the first state to adopt such legislation.

‘I read the lawsuit and, as a matter of fiction, it is a good read,’ Lieu said in a prepared statement after the suit was filed.

‘But from any reasonable legal standard, the lawsuit is frivolous. Under the plaintiffs’ argument, the First Amendment would shield therapists and psychiatrists from medical malpractice and psychological abuse claims simply because they use speech in practicing their medicine. That is a novel and frivolous view of the First Amendment.’

Lieu is not named as a defendant in the lawsuit but several members of the California Board of Behavioral Sciences and the California Mental Board were.

‘Our board voted to support that piece of legislation after working with the author’s office to further define sexual orientation change efforts,’ said Kim Madsen, executive officer for the sciences board, which licenses and oversees therapists.

She had no comment on the lawsuit, but said the board would investigate any complaints of conversion therapy after 1 January.

The law’s critics say that it infringes on the rights of families and therapists, particularly young people who have same-sex attractions as a result of being victims of sexual abuse.

Dacus said the law makes them ‘victims twice, as a result denying them counselling and healing.’

He said that counselling in ‘direct violation’ of religious or personal beliefs, ‘only precipitates greater confusion and depression and the likelihood of suicide.’

The US branch of the World Health Organization has also branded gay ‘cures’ as ineffective and dangerous.